Common (Translated Scientific) Name: Whitebark Pine - Subalpine Fir / Grouse Whortleberry / Common Beargrass Woodland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This minor small- to large-patch community is found primarily in upper subalpine habitats throughout the northern Rocky Mountains from central Idaho north and east into west-central Montana, and northward to the Canadian Rockies of southwestern Alberta. It ranges in elevation from 1585 to 2530 m (5200-8300 feet). The lower elevation occurrences are mostly associated with frost-pocket conditions. It usually occupies moisture-shedding sites from midslope to ridge shoulders and ridgetops; it can be found on well-drained benches in cold-air drainages. Degree of slope is highly variable, but warm aspects (from east-facing through west-facing) are predominant. Parent materials are various, from intrusive volcanics of the Idaho Batholith to extrusive volcanics (andesite and basalt) to various sedimentary and metamorphic species, including quartzite, argillite, siltstone, sandstone and schist. Soils are acidic, well-drained, and soil texture is usually on the coarser end of the spectrum (gravelly sandy loams and loams being common). Exposed rock and soil are generally less than 10%, but rock content in the profile often exceeds 20%. The overstory is usually an open canopy (less than 50% cover) dominated by a variable mix of Abies lasiocarpa, Picea engelmannii, Pinus contorta, and the indicator species Pinus albicaulis, which must have at least 5% cover for this type to be recognized. The undergrowth may be quite dense with a layer of Vaccinium scoparium surrounding clumps of Xerophyllum tenax with a thinly distributed Vaccinium membranaceum superimposed; the combined cover of these three species often exceeds 80%. Tall shrubs, if present, could be characterized as accidentals. Spiraea betulifolia and Lonicera utahensis are consistently scattered in the short-shrub layer. Carex geyeri and Calamagrostis rubescens are the only graminoids regularly present, and their cover seldom exceeds 10%. Other than the abundance of the diagnostic Xerophyllum tenax, the forb layer has low cover and is comparatively depauperate with only Arnica latifolia, Anemone piperi, Goodyera oblongifolia, Orthilia secunda, and Viola orbiculata having a consistent presence.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This association was largely subsumed within the Abies lasiocarpa / Xerophyllum tenax Habitat Type, Vaccinium scoparium Phase (Pfister et al. 1977, Steele et al. 1981, Cooper et al. 1987), in both Idaho and Montana. In accordance with the recent emphasis on creating existing vegetation plant associations, many of the plots used to substantiate the habitat type name cited above would now be classified as ~Pinus contorta / Vaccinium scoparium / Xerophyllum tenax Forest (CEGL005924)$$ or Abies lasiocarpa - Picea engelmannii / Vaccinium scoparium / Xerophyllum tenax Forest (CEGL005914)$$, and a small number have been identified as belonging to the type under consideration. Recognition of a type based on a very minimal cover of a seral tree species (Pinus albicaulis) of broad distribution should provoke questions; the intent of this broadly inclusive type was to capture stands (specifically their locations, particularly in mapping efforts) wherein this highly threatened species occurs or will have once occurred. Considering Vaccinium scoparium and Vaccinium myrtillus as ecological analogues for classification purposes could also create problems, as the ecology of Vaccinium myrtillus is not so well known.

Similar NVC Types: No Data Available

note: No Data Available